Why are there so many flies in the UK?

Brits complain of an unseasonal influx of fruit flies in their homes this autumn

Brits have been complaining of an unseasonal surge in the number of flies inside their homes this autumn.

While the number of house flies can increase over summer, there is traditionally a drop-off in October as colder temperatures come in.

But reports are that in 2026, flies are hanging around.

"I've been living in England for 15 years, but this summer is ridiculous with all these flies," one said on Reddit.

Another added: "I have a mental amount of flies this year too, all different types that I've never even seen before. I sit outside a lot and am constantly batting them off me."

Dr Andrew Whittington, a consultant entomologist at Fly Evidence, told the Telegraph that "the flies are behaving as if it is still late summer".

Here is why there are so many flies and what you can do to battle them.

Experts have said that there are so many flies in the UK because of the record-hot summer.

The UK had an unprecedented five heatwaves this year, with temperatures much higher than normal and a lack of rain leading to drought conditions across the country.

While the heat has meant that tick species have become more resilient, flies have also been a factor for longer periods than usual in the UK.

Dr Whittington said that the warmer-than-usual conditions have brought the breeding cycle from 15 to 20 days down to just 10, giving them more chance to produce offspring.

“The breeding season is slightly prolonged because of the warmer weather, whereas if we’d had a cold snap in late September the populations might have died off.”

He said that cooler temperatures are now being felt, which has meant households are keeping their windows closed, giving the flies no escape.

Flies can be prevented by keeping food stored away and regularly taking out the bins.

Once flies are established, it is best action to clean down the area and keep a window open to encourage them to leave, according to pest expert Matt Lenton, who spoke to the Independent.

Getting rid of the source of any problem, whether it be food or an open bin, is the first step to prevent the flies from coming back. Using an antibacterial spray to wipe down surfaces can also help.